Research and Development of new dielectric Ceramics

研究了介电性能与介电性能之间的关系，以及铁电居里点与元素组合之间的关系。主要研究了具有钙钛矿型晶体结构的材料，这种材料往往具有铁电性。(1)改进了由纤维颗粒组成的钛酸钡陶瓷，使其具有独特的压电现象。纤维状钛酸钡的前驱体为钛酸钾。只观察到了它的平面-伸缩共振，而没有观察到它的厚度共振，尽管普通的压电性材料有这两者。(2)用氢氧化物合成了钛酸铅纤维。纤维溶液的产率和反应温度。得到的钛铅为四方晶系，纤维长度为50-100微米，直径为1-10微米。(3)说明了哪种钙钛矿型铁电材料具有较高或较低的居里点。结果表明，原子间成键的共价键能与居里点高度相关。共价键能较低的钙钛矿型氧化物具有较高的居里点。

Relation between dielectric properties and olientation of grains, synthesis of fibrous grains as starting materials of piezoelectric ceramics, and relation between ferroelectric Curie points and combination of elements were investigated. Materials having perovskite-type crystal structure, which tends to have ferroelectricity, was mainly dealed with.(1) Barium titanate ceramic which made of fibrous grains were inovated, which had a peculiar piezoelectric phenomena. The precurcer of the fibrous barium titanate was potassium titante. Only its planar-extensional resonance was observed and its thickness resonances were not, though ordinary piezoelectrics have both.(2) Lead titanate fibers were synthesized by a hydroxide. The yield of fibrous solution and the reaction temperature. The obtained lead titante was determined to be tetragonal and the fibers were 50-100 um in length and1-10 um in diameter.(3) What kinds of perovskite-type ferroelectrics show a high or low Curie point was illustrated. It was found that the covalent bond energy of interatomic bonding were showing high correlation with Curie points. Perovskite-type oxides with lower covalent bond energy show higher Curie points.